by Paul Bowers
The U.S. Department of Agriculture is on the lookout for Asian gypsy moths in North Charleston and parts of Berkeley County after a local technician found a single specimen of the highly destructive insect in 2014.
In early April, the USDA's Animal and Plant Health Inspection Service set up 1,450 plastic-coated cardboard moth traps in the area. Why the massive hunt for a harmless-looking moth? Because it's far from harmless.
Each female can lay hundreds of eggs at once in fuzzy masses, often in the branches of trees. Once born, the caterpillars have been known to feed on more than 600 species of trees and shrubs. The caterpillars can quickly devour all of the leaves on a tree, leaving it vulnerable to diseases and other pests, before flying long distances and laying eggs elsewhere.
Marjorie Bestwick, supervisor for the USDA APHIS Plant Protection & Quarantine program in North Charleston, says the threat to South Carolina is very real. Because invasive species can come to the United States via foreign ships in the port, her office conducts regular surveys of the Charleston area searching for the Asian gypsy moths.
"They could cause a lot of damage to forestry in South Carolina, which is a multimillion-dollar industry," Bestwick says. "Also, as far as tourism goes, it could affect that as well because a lot of people come here to see the native landscapes, the oak trees in particular, and oak is a host of the Asian gypsy moth. Pine is also a secondary host, and it's a large part of our forest industry in South Carolina."
Since placing this year's glue traps, which are laced with a slow-release attractant pheromone, the USDA has received one specimen from an alert citizen who thought he had caught an Asian gypsy moth — but it turned out to be a false positive. A trap on Cross County Road recently caught a moth, but the USDA is awaiting DNA test results to determine whether it is an Asian gypsy moth.
If another specimen is found this year, the USDA will place more traps in the area and continue its survey. Ultimately, if a threat is identified, the USDA will start looking into ways to neutralize it. One common solution is to spray trees with Bacillus thuringiensis, a naturally occurring bacterium that is toxic to the caterpillars.
"If it comes to that, that's something we would probably work with state and other officials to get that carried out," Bestwick says. "Hopefully it won't come to that issue, but we don't know yet."
If you find a moth that looks like an Asian gypsy moth, the USDA encourages you to contact the local APHIS office at (843) 480-4334.